If your birthday is in August, your birthstone is peridot. And if you have one, you can be sure it came from deep within the Earth—or deep in outer space!

Peridot is the gem name for a gem-quality example of olivine.

Olivine is very common inside the Earth, where it makes up an astonishing 50 percent of Earth’s upper mantle. But it’s much less common on the surface.

It’s found where tectonic forces push mantle up and over Earth’s crust, or where volcanic activity brings up mantle in the form of lava, which can contain peridot crystals.

The most celebrated source of peridot was the tiny Egyptian island of Zabargad, which was pushed up in the region that is now the Red Sea when the African and Asian plates collided 600 million years ago.

Zabargad has been mined since the third century BC and has produced some of the world’s best peridot gemstones. Today, the largest mines are in Myanmar and Pakistan.

A much rarer source of olivine is meteorites that break off from a planet or asteroid large enough to have a mantle then enter Earth’s atmosphere.

These spectacular meteorites contain olivine crystals held in a dark nickel-iron metal matrix. Of the thousands of meteorites found, only 45 contain olivine.

So, if you have a peridot, you can marvel at the long distance it traveled to get to you from deep inside—or far outside—the Earth.